Growth hormone secretion in children and adolescents at high risk for major depressive disorder

Decreased growth hormone (GH) response to pharmacologic stimulation has been found in children and adolescents during an episode of major depressive disorder and after recovery. In this study, we sought to determine whether GH secretion is similarly altered in children and adolescents who had never experienced depression but were at high risk of developing depression.

Subjects were 8 through 16 years of age and selected for high- and low-risk status according to familial loading for mood disorders. Sixty-four high-risk and 55 low-risk healthy subjects participated in the study, which assessed the following GH measures: (1) GH before growth hormone-releasing hormone (GHRH) infusion, every 15 minutes for 30 minutes; (2) GH response after intravenous infusion of GHRH (0.1 microg/kg), every 15 minutes for 90 minutes; and (3) nocturnal GH every 20 minutes from 9 PM until morning awakening.

After stimulation with GHRH, the high-risk subjects secreted significantly less GH compared with the low-risk healthy controls (effect sizes for mean and peak GH, 0.52 [P =.007] and 0.40 [P =.04], respectively). In contrast, there were no between-group differences in the pre-GHRH and nocturnal GH secretion levels. Exposure to recent stressors was not associated with GH secretion.

Taken together with previous evidence of decreased GH after GHRH infusion in acutely depressed and recovered children, these results indicate that the decreased GH response found in high-risk subjects may represent a trait marker for depression in children and adolescents.